Conventional wisdom says that what you don't know can't hurt you. Unfortunately, that's not the case when it comes to personal care products and cosmetics.

A study by the Campaign for Safe Cosmetics indicates that women use an average of nine personal care products each day, exposing themselves to a mixture of over 100 individual chemicals. In 2003, the Centers for Disease Control and Prevention reported that women had significantly higher levels of 10 of the 116 toxic chemicals they tested for than men. Three of the 10 chemicals were phthalates, a group commonly found in health and beauty products and linked to birth defects (PDF). In fact, almost any chemical – including those linked to breast cancer, hormone disruption, reproductive problems, and allergies – can be used in cosmetics.

How is this possible? One reason is weak government regulation. The 1938 US law that governs the US cosmetic industry contains loopholes big enough for an elephant to jump through.

Under the law, the Food and Drug Administration (FDA) requires companies to assure that their products are safe for use, but they aren't given any authority to conduct pre-market testing of products. Therefore the safety of personal care product ingredients lies with an industry-funded body, the Cosmetic Ingredient Review (CIR) panel. The panel has only found 11 chemicals unsafe for use in cosmetics. Even when the panel recommends prohibition of an ingredient, there is no penalty for companies who ignore those recommendations.

The FDA is put in the position of playing defence, trying to pull bad products off the shelf – only after enough consumers have reported health problems to warrant attention. Even then, it has very little power. It can only ask manufacturers to recall a product voluntarily. It doesn't have to be this way. The EU has banned more than 1,300 chemicals from personal care products because of links to cancer, birth defects and reproductive harm, although the US only bans 11.

Chemicals of concern found in cosmetics include lead acetate, phthalates, nanoparticles and petrochemicals, among others. Two chemicals of particularly high concern – hydroquinone and formaldehyde – are common ingredients in products marketed to women of colour, promising lighter skin and straighter hair. These also sell an extremely troubling message about what beauty looks like.

"Fragrance" is also a problem because it is an umbrella term representing a mixture of 100 or more ingredients that may contain any of 3,000 different chemicals including carcinogens, reproductive toxins, hormone disruptors, and allergens. The current US Food, Drug and Cosmetics Act allows fragrance ingredients to be kept as trade secrets, meaning that consumers are kept in the dark about the chemicals they are exposed to from scented products. Regulators have no way of knowing what potentially harmful ingredients might be contained in those products.

Ultimately, consumer pressure will convince companies to do the right thing by eliminating toxic chemicals and transparently listing all their ingredients. Consumers are getting more sophisticated by the day, becoming more familiar with the names of chemicals they are eager to avoid. With women making roughly 85% of household purchasing decisions in the US, companies would do right to listen to their customers' concerns.

Once companies start making these shifts, the passage of proposed laws such as the Safe Cosmetics and Personal Care Products Act of 2013 (which would give the FDA the authority it needs to regulate products effectively) will be possible.